Mercurial > dropbear

comparison svr-main.c @ 302:973fccb59ea4 ucc-axis-hack

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propagate from branch 'au.asn.ucc.matt.dropbear' (head 11034278bd1917bebcbdc69cf53b1891ce9db121) to branch 'au.asn.ucc.matt.dropbear.ucc-axis-hack' (head 10a1f614fec73d0820c3f61160d9db409b9beb46)
author Matt Johnston <matt@ucc.asn.au>
date Sat, 25 Mar 2006 12:59:58 +0000
parents 740e782679be 7dad470ad4aa
children 474c1a700b67
comparison
equal deleted inserted replaced
299:740e782679be 302:973fccb59ea4
1 /* 1 /*
2 * Dropbear - a SSH2 server 2 * Dropbear - a SSH2 server
3 * 3 *
4 * Copyright (c) 2002,2003 Matt Johnston 4 * Copyright (c) 2002-2006 Matt Johnston
5 * All rights reserved. 5 * All rights reserved.
6 * 6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal 8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights 9 * in the Software without restriction, including without limitation the rights
26 #include "dbutil.h" 26 #include "dbutil.h"
27 #include "session.h" 27 #include "session.h"
28 #include "buffer.h" 28 #include "buffer.h"
29 #include "signkey.h" 29 #include "signkey.h"
30 #include "runopts.h" 30 #include "runopts.h"
31 31 #include "random.h"
32 static int listensockets(int *sock, int sockcount, int *maxfd); 32
33 static size_t listensockets(int *sock, size_t sockcount, int *maxfd);
33 static void sigchld_handler(int dummy); 34 static void sigchld_handler(int dummy);
34 static void sigsegv_handler(int); 35 static void sigsegv_handler(int);
35 static void sigintterm_handler(int fish); 36 static void sigintterm_handler(int fish);
36 #ifdef INETD_MODE 37 #ifdef INETD_MODE
37 static void main_inetd(); 38 static void main_inetd();
39 #ifdef NON_INETD_MODE 40 #ifdef NON_INETD_MODE
40 static void main_noinetd(); 41 static void main_noinetd();
41 #endif 42 #endif
42 static void commonsetup(); 43 static void commonsetup();
43 44
44 static int childpipes[MAX_UNAUTH_CLIENTS];
45
46 #if defined(DBMULTI_dropbear) || !defined(DROPBEAR_MULTI) 45 #if defined(DBMULTI_dropbear) || !defined(DROPBEAR_MULTI)
47 #if defined(DBMULTI_dropbear) && defined(DROPBEAR_MULTI) 46 #if defined(DBMULTI_dropbear) && defined(DROPBEAR_MULTI)
48 int dropbear_main(int argc, char ** argv) 47 int dropbear_main(int argc, char ** argv)
49 #else 48 #else
50 int main(int argc, char ** argv) 49 int main(int argc, char ** argv)
51 #endif 50 #endif
52 { 51 {
53
54
55 _dropbear_exit = svr_dropbear_exit; 52 _dropbear_exit = svr_dropbear_exit;
56 _dropbear_log = svr_dropbear_log; 53 _dropbear_log = svr_dropbear_log;
57 54
58 /* get commandline options */ 55 /* get commandline options */
59 svr_getopts(argc, argv); 56 svr_getopts(argc, argv);
78 75
79 #ifdef INETD_MODE 76 #ifdef INETD_MODE
80 static void main_inetd() { 77 static void main_inetd() {
81 78
82 struct sockaddr_storage remoteaddr; 79 struct sockaddr_storage remoteaddr;
83 int remoteaddrlen; 80 socklen_t remoteaddrlen;
84 char * addrstring = NULL; 81 char * addrstring = NULL;
85 82
86 /* Set up handlers, syslog */ 83 /* Set up handlers, syslog, seed random */
87 commonsetup(); 84 commonsetup();
88 85
89 remoteaddrlen = sizeof(remoteaddr); 86 remoteaddrlen = sizeof(remoteaddr);
90 if (getpeername(0, (struct sockaddr*)&remoteaddr, &remoteaddrlen) < 0) { 87 if (getpeername(0, (struct sockaddr*)&remoteaddr, &remoteaddrlen) < 0) {
91 dropbear_exit("Unable to getpeername: %s", strerror(errno)); 88 dropbear_exit("Unable to getpeername: %s", strerror(errno));
114 fd_set fds; 111 fd_set fds;
115 struct timeval seltimeout; 112 struct timeval seltimeout;
116 unsigned int i, j; 113 unsigned int i, j;
117 int val; 114 int val;
118 int maxsock = -1; 115 int maxsock = -1;
119 struct sockaddr_storage remoteaddr;
120 int remoteaddrlen;
121 int listensocks[MAX_LISTEN_ADDR]; 116 int listensocks[MAX_LISTEN_ADDR];
122 int listensockcount = 0; 117 size_t listensockcount = 0;
123 FILE *pidfile = NULL; 118 FILE *pidfile = NULL;
124 119
120 int childpipes[MAX_UNAUTH_CLIENTS];
121 char * preauth_addrs[MAX_UNAUTH_CLIENTS];
122
125 int childsock; 123 int childsock;
126 pid_t childpid;
127 int childpipe[2]; 124 int childpipe[2];
128 125
129 /* fork */ 126 /* fork */
130 if (svr_opts.forkbg) { 127 if (svr_opts.forkbg) {
131 int closefds = 0; 128 int closefds = 0;
139 } 136 }
140 } 137 }
141 138
142 commonsetup(); 139 commonsetup();
143 140
144
145 /* should be done after syslog is working */ 141 /* should be done after syslog is working */
146 if (svr_opts.forkbg) { 142 if (svr_opts.forkbg) {
147 dropbear_log(LOG_INFO, "Running in background"); 143 dropbear_log(LOG_INFO, "Running in background");
148 } else { 144 } else {
149 dropbear_log(LOG_INFO, "Not forking"); 145 dropbear_log(LOG_INFO, "Not forking");
158 154
159 /* sockets to identify pre-authenticated clients */ 155 /* sockets to identify pre-authenticated clients */
160 for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) { 156 for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) {
161 childpipes[i] = -1; 157 childpipes[i] = -1;
162 } 158 }
159 bzero(preauth_addrs, sizeof(preauth_addrs));
163 160
164 /* Set up the listening sockets */ 161 /* Set up the listening sockets */
165 /* XXX XXX ports */
166 listensockcount = listensockets(listensocks, MAX_LISTEN_ADDR, &maxsock); 162 listensockcount = listensockets(listensocks, MAX_LISTEN_ADDR, &maxsock);
167 if (listensockcount < 0) { 163 if (listensockcount == 0)
164 {
168 dropbear_exit("No listening ports available."); 165 dropbear_exit("No listening ports available.");
169 } 166 }
170 167
171 /* incoming connection select loop */ 168 /* incoming connection select loop */
172 for(;;) { 169 for(;;) {
175 172
176 seltimeout.tv_sec = 60; 173 seltimeout.tv_sec = 60;
177 seltimeout.tv_usec = 0; 174 seltimeout.tv_usec = 0;
178 175
179 /* listening sockets */ 176 /* listening sockets */
180 for (i = 0; i < (unsigned int)listensockcount; i++) { 177 for (i = 0; i < listensockcount; i++) {
181 FD_SET(listensocks[i], &fds); 178 FD_SET(listensocks[i], &fds);
182 } 179 }
183 180
184 /* pre-authentication clients */ 181 /* pre-authentication clients */
185 for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) { 182 for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) {
206 continue; 203 continue;
207 } 204 }
208 dropbear_exit("Listening socket error"); 205 dropbear_exit("Listening socket error");
209 } 206 }
210 207
211 /* close fds which have been authed or closed - auth.c handles 208 /* close fds which have been authed or closed - svr-auth.c handles
212 * closing the auth sockets on success */ 209 * closing the auth sockets on success */
213 for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) { 210 for (i = 0; i < MAX_UNAUTH_CLIENTS; i++) {
214 if (childpipes[i] >= 0 && FD_ISSET(childpipes[i], &fds)) { 211 if (childpipes[i] >= 0 && FD_ISSET(childpipes[i], &fds)) {
215 close(childpipes[i]); 212 m_close(childpipes[i]);
216 childpipes[i] = -1; 213 childpipes[i] = -1;
214 m_free(preauth_addrs[i]);
217 } 215 }
218 } 216 }
219 217
220 /* handle each socket which has something to say */ 218 /* handle each socket which has something to say */
221 for (i = 0; i < (unsigned int)listensockcount; i++) { 219 for (i = 0; i < listensockcount; i++) {
220
221 struct sockaddr_storage remoteaddr;
222 socklen_t remoteaddrlen = 0;
223 size_t num_unauthed_for_addr = 0;
224 size_t num_unauthed_total = 0;
225 char * remote_addr_str = NULL;
226 pid_t fork_ret = 0;
227 size_t conn_idx = 0;
228
222 if (!FD_ISSET(listensocks[i], &fds)) 229 if (!FD_ISSET(listensocks[i], &fds))
223 continue; 230 continue;
224 231
225 remoteaddrlen = sizeof(remoteaddr); 232 remoteaddrlen = sizeof(remoteaddr);
226 childsock = accept(listensocks[i], 233 childsock = accept(listensocks[i],
229 if (childsock < 0) { 236 if (childsock < 0) {
230 /* accept failed */ 237 /* accept failed */
231 continue; 238 continue;
232 } 239 }
233 240
234 /* check for max number of connections not authorised */ 241 /* Limit the number of unauthenticated connections per IP */
242 remote_addr_str = getaddrstring(&remoteaddr, 0);
243
244 num_unauthed_for_addr = 0;
245 num_unauthed_total = 0;
235 for (j = 0; j < MAX_UNAUTH_CLIENTS; j++) { 246 for (j = 0; j < MAX_UNAUTH_CLIENTS; j++) {
236 if (childpipes[j] < 0) { 247 if (childpipes[j] >= 0) {
237 break; 248 num_unauthed_total++;
249 if (strcmp(remote_addr_str, preauth_addrs[j]) == 0) {
250 num_unauthed_for_addr++;
251 }
252 } else {
253 /* a free slot */
254 conn_idx = j;
238 } 255 }
239 } 256 }
240 257
241 if (j == MAX_UNAUTH_CLIENTS) { 258 if (num_unauthed_total >= MAX_UNAUTH_CLIENTS
242 /* no free connections */ 259 || num_unauthed_for_addr >= MAX_UNAUTH_PER_IP) {
243 /* TODO - possibly log, though this would be an easy way 260 goto out;
244 * to fill logs/disk */
245 close(childsock);
246 continue;
247 } 261 }
248 262
249 if (pipe(childpipe) < 0) { 263 if (pipe(childpipe) < 0) {
250 TRACE(("error creating child pipe")) 264 TRACE(("error creating child pipe"))
251 close(childsock); 265 goto out;
252 continue; 266 }
253 } 267
254 268 fork_ret = fork();
255 if ((childpid = fork()) == 0) { 269 if (fork_ret < 0) {
270 dropbear_log(LOG_WARNING, "error forking: %s", strerror(errno));
271 goto out;
272
273 } else if (fork_ret > 0) {
274
275 /* parent */
276 childpipes[conn_idx] = childpipe[0];
277 m_close(childpipe[1]);
278 preauth_addrs[conn_idx] = remote_addr_str;
279 remote_addr_str = NULL;
280
281 } else {
256 282
257 /* child */ 283 /* child */
258 char * addrstring = NULL; 284 char * addrstring = NULL;
259 #ifdef DEBUG_FORKGPROF 285 #ifdef DEBUG_FORKGPROF
260 extern void _start(void), etext(void); 286 extern void _start(void), etext(void);
261 monstartup((u_long)&_start, (u_long)&etext); 287 monstartup((u_long)&_start, (u_long)&etext);
262 #endif /* DEBUG_FORKGPROF */ 288 #endif /* DEBUG_FORKGPROF */
263 289
290 m_free(remote_addr_str);
264 addrstring = getaddrstring(&remoteaddr, 1); 291 addrstring = getaddrstring(&remoteaddr, 1);
265 dropbear_log(LOG_INFO, "Child connection from %s", addrstring); 292 dropbear_log(LOG_INFO, "Child connection from %s", addrstring);
266 293
267 if (setsid() < 0) { 294 if (setsid() < 0) {
268 dropbear_exit("setsid: %s", strerror(errno)); 295 dropbear_exit("setsid: %s", strerror(errno));
269 } 296 }
270 297
271 /* make sure we close sockets */ 298 /* make sure we close sockets */
272 for (i = 0; i < (unsigned int)listensockcount; i++) { 299 for (i = 0; i < listensockcount; i++) {
273 if (m_close(listensocks[i]) == DROPBEAR_FAILURE) { 300 m_close(listensocks[i]);
274 dropbear_exit("Couldn't close socket");
275 }
276 } 301 }
277 302
278 if (m_close(childpipe[0]) == DROPBEAR_FAILURE) { 303 m_close(childpipe[0]);
279 dropbear_exit("Couldn't close socket");
280 }
281 304
282 /* start the session */ 305 /* start the session */
283 svr_session(childsock, childpipe[1], 306 svr_session(childsock, childpipe[1],
284 getaddrhostname(&remoteaddr), 307 getaddrhostname(&remoteaddr),
285 addrstring); 308 addrstring);
286 /* don't return */ 309 /* don't return */
287 dropbear_assert(0); 310 dropbear_assert(0);
288 } 311 }
289 312
290 /* parent */ 313 out:
291 childpipes[j] = childpipe[0]; 314 /* This section is important for the parent too */
292 if (m_close(childpipe[1]) == DROPBEAR_FAILURE 315 m_close(childsock);
293 || m_close(childsock) == DROPBEAR_FAILURE) { 316 if (remote_addr_str) {
294 dropbear_exit("Couldn't close socket"); 317 m_free(remote_addr_str);
295 } 318 }
296 } 319 }
297 } /* for(;;) loop */ 320 } /* for(;;) loop */
298 321
299 /* don't reach here */ 322 /* don't reach here */
357 } 380 }
358 381
359 /* Now we can setup the hostkeys - needs to be after logging is on, 382 /* Now we can setup the hostkeys - needs to be after logging is on,
360 * otherwise we might end up blatting error messages to the socket */ 383 * otherwise we might end up blatting error messages to the socket */
361 loadhostkeys(); 384 loadhostkeys();
385
386 seedrandom();
362 } 387 }
363 388
364 /* Set up listening sockets for all the requested ports */ 389 /* Set up listening sockets for all the requested ports */
365 static int listensockets(int *sock, int sockcount, int *maxfd) { 390 static size_t listensockets(int *sock, size_t sockcount, int *maxfd) {
366 391
367 unsigned int i; 392 unsigned int i;
368 char* errstring = NULL; 393 char* errstring = NULL;
369 unsigned int sockpos = 0; 394 size_t sockpos = 0;
370 int nsock; 395 int nsock;
371 396
372 TRACE(("listensockets: %d to try\n", svr_opts.portcount)) 397 TRACE(("listensockets: %d to try\n", svr_opts.portcount))
373 398
374 for (i = 0; i < svr_opts.portcount; i++) { 399 for (i = 0; i < svr_opts.portcount; i++) {